Magnetic memory devices

ABSTRACT

A magnetic memory device includes a magnetic tunnel junction pattern on a substrate, a first conductive pattern between the substrate and the magnetic tunnel junction pattern, lower contact plugs between the first conductive pattern and the substrate and disposed at respective sides of the magnetic tunnel junction pattern, and second conductive patterns on the lower contact plugs, respectively. The second conductive patterns connect the lower contact plugs to the first conductive pattern. The second conductive patterns include a ferromagnetic material.

CROSS-REFERENCE TO RELATED APPLICATION

This U.S. non-provisional patent application claims priority under 35U.S.C. § 119 to Korean Patent Application No. 10-2019-0113440, filed onSep. 16, 2019, in the Korean Intellectual Property Office, thedisclosure of which is hereby incorporated by reference in its entirety.

FIELD

Embodiments of the inventive concepts relate to semiconductor devicesand, more particularly, to magnetic memory devices including magnetictunnel junctions.

BACKGROUND

As demand for high-speed and/or low power consumption electronic deviceshas increased, so has demand for high-speed and/or low-voltagesemiconductor memory devices used therein. Magnetic memory devices havebeen developed as semiconductor memory devices that may be capable ofsatisfying this demand. The magnetic memory devices may emerge asnext-generation semiconductor memory devices because of their high-speedand/or non-volatile characteristics.

Generally, a magnetic memory device may include a magnetic tunneljunction (MTJ). The magnetic tunnel junction may include two magneticlayers and an insulating layer disposed between the two magnetic layers.A resistance value of the magnetic tunnel junction may be changeddepending on magnetization directions of the two magnetic layers. Themagnetic memory device may write/read data using a difference betweenthe resistance values of the magnetic tunnel junction. Highly integratedand/or low-power magnetic memory devices have been increasingly demandedwith the development of an electronic industry. Thus, various researchis ongoing to satisfy this demand.

SUMMARY

Embodiments of the inventive concepts may provide magnetic memorydevices capable of reducing a switching current.

Embodiments of the inventive concepts may also provide magnetic memorydevices capable of allowing a magnetization direction of a free layer tobe more easily aligned in a perpendicular direction after switching thefree layer.

In some embodiments, a magnetic memory device may include a magnetictunnel junction pattern on a substrate, a first conductive patternbetween the substrate and the magnetic tunnel junction pattern, lowercontact plugs between the first conductive pattern and the substrate anddisposed at respective sides of the magnetic tunnel junction pattern,and second conductive patterns on the lower contact plugs, respectively.The second conductive patterns may connect the lower contact plugs tothe first conductive pattern. The second conductive patterns may includea ferromagnetic material.

In some embodiments, a magnetic memory device may include magnetictunnel junction patterns arranged along and spaced apart in a firstdirection on a substrate, first conductive patterns under bottomsurfaces of the magnetic tunnel junction patterns, respectively, andlower conductive patterns between the substrate and the first conductivepatterns. The lower conductive patterns may be disposed between themagnetic tunnel junction patterns in a plan view, and may connectadjacent ones of the first conductive patterns. The lower conductivepatterns may include first lower conductive patterns and second lowerconductive patterns, which are alternately arranged in the firstdirection. The first and second lower conductive patterns may have firstand second magnetization directions, respectively, that are fixed inopposite directions to each other.

In some embodiments, a magnetic memory device may include magnetictunnel junction patterns arranged along and spaced apart in a firstdirection on a substrate, first conductive patterns under bottomsurfaces of the magnetic tunnel junction patterns, respectively, andsecond conductive patterns between the substrate and the firstconductive patterns and including a ferromagnetic material. The secondconductive patterns may be disposed between the magnetic tunnel junctionpatterns in a plan view, and may connect adjacent ones of the firstconductive patterns. The second conductive patterns may include firstpatterns disposed at first sides of the first conductive patterns, andsecond patterns disposed at second sides of the first conductivepatterns. A cross-sectional area of each of the second patterns may begreater than a cross-sectional area of each of the first patterns.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concepts will become more apparent in view of the attacheddrawings and accompanying detailed description.

FIG. 1 is a plan view illustrating a magnetic memory device according tosome embodiments of the inventive concepts.

FIG. 2 is a cross-sectional view taken along a line I-I′ of FIG. 1.

FIGS. 3 and 5 are enlarged views of a portion ‘A’ of FIG. 2.

FIG. 4 is a conceptual diagram illustrating a change in a magnetizationdirection of a first magnetic pattern.

FIG. 6 is a plan view illustrating a magnetic memory device according tosome embodiments of the inventive concepts.

FIGS. 7, 9, 11, 13, 15 and 17 are plan views illustrating a method ofmanufacturing a magnetic memory device, according to some embodiments ofthe inventive concepts.

FIGS. 8, 10, 12, 14, 16 and 18 are cross-sectional views taken alonglines I-I′ of FIGS. 7, 9, 11, 13, 15 and 17, respectively.

FIG. 19 is a cross-sectional view corresponding to the line I-I′ of FIG.1 to illustrate a magnetic memory device according to some embodimentsof the inventive concepts.

FIGS. 20 to 22 are cross-sectional views taken along the line I-I′ ofFIG. 1 to illustrate a method of manufacturing a magnetic memory device,according to some embodiments of the inventive concepts.

FIG. 23 is a plan view illustrating a magnetic memory device accordingto some embodiments of the inventive concepts.

FIG. 24 is a cross-sectional view taken along a line I-I′ of FIG. 23.

FIGS. 25 and 27 are plan views illustrating a method of manufacturing amagnetic memory device, according to some embodiments of the inventiveconcepts.

FIGS. 26 and 28 are cross-sectional views taken along lines I-I′ ofFIGS. 25 and 27, respectively.

FIG. 29 is a cross-sectional view taken along the line I-I′ of FIG. 1illustrating a magnetic memory device according to some embodiments ofthe inventive concepts.

FIG. 30 is a cross-sectional view taken along the line I-I′ of FIG. 1illustrating a magnetic memory device according to some embodiments ofthe inventive concepts.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments of the inventive concepts will be described indetail with reference to the accompanying drawings.

FIG. 1 is a plan view illustrating a magnetic memory device according tosome embodiments of the inventive concepts. FIG. 2 is a cross-sectionalview taken along a line I-I′ of FIG. 1. FIGS. 3 and 5 are enlarged viewsof a portion ‘A’ of FIG. 2. FIG. 4 is a conceptual diagram illustratinga change in a magnetization direction of a first magnetic pattern. Theterms first, second, etc. are used herein to distinguish elements,parameters, and/or operations from one another, rather than for purposesof limitation, and a first element discussed below could be termed asecond element without departing from the scope of the present inventiveconcepts.

Referring to FIGS. 1 to 5, lower conductive patterns may be disposed ona substrate 100. In the present specification, the lower conductivepatterns may refer to second conductive patterns to be described lateror may refer to the second conductive patterns and lower contact plugs120 disposed thereunder. Lower contact plugs 120 and a first interlayerinsulating layer 111 between the lower contact plugs 120 may be disposedon the substrate 100. The substrate 100 may include a semiconductorsubstrate and selection elements SW formed on the semiconductorsubstrate. The semiconductor substrate may include silicon (Si), siliconon an insulator (SOI), silicon-germanium (SiGe), germanium (Ge), orgallium-arsenide (GaAs). The selection elements SW may be field effecttransistors or diodes. Spatially relative terms, such as “beneath,”“below,” “lower,” “above,” “upper,” and the like, may be used herein forease of description to describe one element's or feature's relationshipto another element(s) or feature(s) as illustrated in the figures. Itwill be understood that the spatially relative terms are intended toencompass different orientations of the device in use or operation inaddition to the orientation depicted in the figures.

The lower contact plugs 120 may be laterally spaced apart from eachother. The lower contact plugs 120 may be arranged to be spaced apart atintervals in a first direction D1 parallel to a top surface 100U of thesubstrate 100. For example, the lower contact plugs 120 may be arrangedin the first direction D1 and a third direction D3. The third directionD3 may be parallel to the top surface 100U of the substrate 100 and mayintersect the first direction D1. Odd-numbered lower contact plugs 120of the lower contact plugs 120 arranged in the first direction D1 may bereferred to as first lower contact plugs 120A, and even-numbered lowercontact plugs 120 thereof may be referred to as second lower contactplugs 120B. In other words, the first lower contact plugs 120A and thesecond lower contact plugs 120B may be alternately arranged oralternating in the first direction D1.

Each of the lower contact plugs 120 may be connected to one terminal ofa corresponding one of the selection elements SW. As used herein, theterm “connected” may refer to physical and/or electrical connection. Thelower contact plugs 120 may include a doped semiconductor material(e.g., doped silicon), a metal (e.g., tungsten, titanium, or tantalum),a conductive metal nitride (e.g., titanium nitride, tantalum nitride, ortungsten nitride), and/or a metal-semiconductor compound (e.g., a metalsilicide). The lower contact plugs 120 may be electrically isolated fromeach other by the first interlayer insulating layer 111. The firstinterlayer insulating layer 111 may include an oxide layer, a nitridelayer, and/or an oxynitride layer.

Second conductive patterns 191 and 192 may be provided on the lowercontact plugs 120, respectively. The second conductive patterns 191 and192 may be disposed in a second interlayer insulating layer 112 providedon the first interlayer insulating layer 111. The second interlayerinsulating layer 112 may include an oxide layer, a nitride layer, and/oran oxynitride layer. The second conductive patterns 191 and 192 mayinclude first patterns 191 on the first lower contact plugs 120A andsecond patterns 192 on the second lower contact plugs 120B. Sidewalls ofthe second conductive patterns 191 and 192 may be aligned with sidewallsof the lower contact plugs 120. Thicknesses of the second conductivepatterns 191 and 192 may be less than thicknesses of the lower contactplugs 120. Each of the second conductive patterns 191 and 192 may havesubstantially the same shape as the lower contact plug 120 disposedthereunder when viewed in a plan view.

Magnetic tunnel junction patterns MTJ may be disposed on the secondinterlayer insulating layer 112 and may be laterally spaced apart fromeach other. The magnetic tunnel junction patterns MTJ may be arranged tobe spaced apart at intervals in the first direction D1. Each of themagnetic tunnel junction patterns MTJ may be disposed on the secondinterlayer insulating layer 112 between a pair of the lower contactplugs 120 that are immediately adjacent to each other. Respective pairsof lower contact plugs 120 may be disposed at both (e.g., opposing)sides of each of the magnetic tunnel junction patterns MTJ, and betweenimmediately adjacent magnetic tunnel junction patterns MTJ. Each of themagnetic tunnel junction patterns MTJ may include a first magneticpattern MP1, a tunnel barrier pattern TBP and a second magnetic patternMP2, which are sequentially stacked in a second direction D2intersecting (e.g., perpendicular to) the first and third directions D1and D3. The tunnel barrier pattern TBP may be disposed between the firstmagnetic pattern MP1 and the second magnetic pattern MP2. For example,the tunnel barrier pattern TBP may include a magnesium oxide (MgO)layer, a titanium oxide (TiO) layer, an aluminum oxide (AlO) layer, amagnesium-zinc oxide (MgZnO) layer, and/or a magnesium-boron oxide(MgBO) layer. Each of the first and second magnetic patterns MP1 and MP2may include at least one magnetic layer.

As illustrated in FIGS. 3 and 5, the second magnetic pattern MP2 mayinclude a reference layer having a magnetization direction M2 fixed inone direction, and the first magnetic pattern MP1 may include a freelayer having a magnetization direction M1 changeable to be parallel oranti-parallel to the magnetization direction M2 of the reference layer.In some embodiments, as illustrated in FIG. 3, the magnetizationdirections M1 and M2 may be substantially perpendicular to an interfacebetween the tunnel barrier pattern TBP and the first magnetic patternMP. In this case, each of the reference layer and the free layer mayinclude a perpendicular magnetic material (e.g., CoFeTb, CoFeGd, orCoFeDy), a perpendicular magnetic material having a L1 ₀ structure, aCoPt alloy having a hexagonal close packed (HCP) lattice structure,and/or a perpendicular magnetic structure. The perpendicular magneticmaterial having the L1 ₀ structure may include FePt having the L1 ₀structure, FePd having the L1 ₀ structure, CoPd having the L1 ₀structure, and/or CoPt having the L1 structure. The perpendicularmagnetic structure may include magnetic layers and non-magnetic layers,which are alternately and repeatedly stacked. For example, theperpendicular magnetic structure may include (Co/Pt)n, (CoFe/Pt)n,(CoFe/Pd)n, (Co/Pd)n, (Co/Ni)n, (CoNi/Pt)n, (CoCr/Pt)n, and/or(CoCr/Pd)n, where “n” denotes the number of bilayers. Here, thereference layer may be thicker than the free layer, and/or a coerciveforce of the reference layer may be greater than a coercive force of thefree layer.

Electrode patterns 160 may be disposed on the magnetic tunnel junctionpatterns MTJ, respectively. The first magnetic pattern MP1 may bedisposed between the second interlayer insulating layer 112 and thetunnel barrier pattern TBP, and the second magnetic pattern MP2 may bedisposed between each of the electrode patterns 160 and the tunnelbarrier pattern TBP. For example, the electrode patterns 160 may includea metal (e.g., Ta, W, Ru, or Ir) and/or a conductive metal nitride(e.g., TiN).

First conductive patterns 150 may be disposed under the magnetic tunneljunction patterns MTJ, respectively. A pair of the second conductivepatterns 191 and 192 adjacent to each of the magnetic tunnel junctionpatterns MTJ may be connected to both end portions of each of the firstconductive patterns 150, respectively. For example, the first pattern191 may be connected to one end portion E1 of the first conductivepattern 150, and the second pattern 192 may be connected to another endportion E2 of the first conductive pattern 150. The one end portion E1and the other end portion E2 may be spaced apart from each other in thefirst direction D1. One end portion of each of the second conductivepatterns 191 and 192 may be connected to one of the first conductivepatterns 150, and another end portion thereof may be connected toanother of the first conductive patterns 150. Bottom surfaces of thefirst conductive patterns 150 may be in contact with a top surface ofthe second interlayer insulating layer 112.

The first conductive patterns 150 and the second conductive patterns 191and 192 may be alternately arranged in the first direction D1. Each ofthe second conductive patterns 191 and 192 may be disposed between themagnetic tunnel junction patterns MTJ in a plan view and may connect thefirst conductive patterns 150 immediately adjacent to each other.

A third interlayer insulating layer 170 may be disposed on the secondconductive patterns 191 and 192 to cover the magnetic tunnel junctionpatterns MTJ and the electrode patterns 160. For example, the thirdinterlayer insulating layer 170 may cover sidewalls of the magnetictunnel junction patterns MTJ and the electrode patterns 160. The thirdinterlayer insulating layer 170 may include an oxide layer, a nitridelayer, and/or an oxynitride layer. Upper conductive lines 200 may bedisposed on the third interlayer insulating layer 170. The upperconductive lines 200 may be connected to the magnetic tunnel junctionpatterns MTJ, respectively. Each of the upper conductive lines 200 maybe electrically connected to a corresponding one of the magnetic tunneljunction patterns MTJ through a corresponding one of the electrodepatterns 160. For example, the upper conductive lines 200 may extend inthe third direction D3 and may be spaced apart from each other in thefirst direction D1.

Each of the upper conductive lines 200 may extend in the third directionD3 and may be connected to a plurality of the electrode patterns 160 andthe magnetic tunnel junction patterns MTJ thereunder. The upperconductive lines 200 may include a metal (e.g., copper) and/or aconductive metal nitride. The upper conductive lines 200 may be used asbit lines.

FIG. 3 illustrates a first in-plane current Jc1 that flows through thefirst conductive pattern 150 in a direction opposite to the firstdirection D1. FIG. 4 is a conceptual diagram illustrating a change inthe magnetization direction M1 of the first magnetic pattern MP1. In thepresent specification, the term ‘in-plane’ may mean a direction parallelto a specific surface of a corresponding component and may mean adirection parallel to the top surface 100U of the substrate 100 and/or adirection parallel to the interface between the tunnel barrier patternTBP and the first magnetic pattern MP1, unless otherwise defined.Likewise, ‘a perpendicular direction’ may mean a direction (e.g., thesecond direction D2 or a direction opposite to the second direction D2)perpendicular to the top surface 100U of the substrate 100 and/or adirection perpendicular to the interface between the tunnel barrierpattern TBP and the first magnetic pattern MP1, unless otherwisedefined.

A current provided from a first selection element SW1 connected to aninterconnection line CL may sequentially pass through the first lowercontact plug 120A, the first pattern 191, the first conductive pattern150, the second pattern 192, and the second lower contact plug 120B andthen may be transmitted to a second selection element SW2. In this case,electrons may move from the second selection element SW2 to the firstselection element SW1 through a path opposite to the above path.

The first conductive patterns 150 may be configured to apply spin-orbittorque to the magnetic tunnel junction patterns MTJ. The firstconductive patterns 150 may be configured to have strong spin-orbitinteraction. The first in-plane current Jc1 flowing through the firstconductive pattern 150 may cause accumulation of spin-polarized chargecarriers (e.g., electrons) near the magnetic tunnel junction pattern MTJby the spin-orbit interaction in the first conductive pattern 150. Aspin-orbit field may be generated by the accumulated charge carriers.The spin-orbit field may be in-plane of the first conductive pattern 150and may be perpendicular to a direction of the in-plane current flowingthrough the first conductive pattern 150. For example, the firstin-plane current Jc1 may flow in the direction opposite to the firstdirection D1, and the spin-orbit field may be parallel to the thirddirection D3. The spin-orbit field generated in the first conductivepattern 150 may apply the spin-orbit torque to the magnetic tunneljunction pattern MTJ (more particularly, the magnetization direction M1of the first magnetic pattern MP1). Thus, an initial magnetizationdirection Ma of the first magnetic pattern MP1 may be switched to afinal magnetization direction Mc opposite to the initial magnetizationdirection Ma by using the spin-orbit torque. In FIG. 3, the initialmagnetization direction Ma may be the direction opposite to the seconddirection D2, and the final magnetization direction Mc may be the seconddirection D2.

The first in-plane current Jc1 and the spin-orbit field generatedthereby may have components in an in-plane direction, which are strongerthan components in the perpendicular direction (e.g., the seconddirection D2 or the direction opposite to the second direction D2).Thus, the initial magnetization direction Ma of the first magneticpattern MP1 may be relatively easily changed into a middle magnetizationdirection Mb, which is in-plane, e.g., parallel to a bottom surface IPof the first magnetic pattern MP1, by first torque RQL. Torque in theperpendicular direction may be required to change the middlemagnetization direction Mb into the final magnetization direction Mc.However, the first in-plane current Jc1 and the spin-orbit fieldgenerated thereby may have the strong components in the in-planedirection as described above, and thus the change into the finalmagnetization direction Mc may not be easy. Accordingly,non-deterministic switching in which a final magnetization direction isnot accurately determined may occur.

According to some embodiments of the inventive concepts, the secondconductive patterns 191 and 192 may have magnetization directions Mu andMd perpendicular to the top surface 100U of the substrate 100, therebyenhancing a perpendicular component of second torque RQ2 for changingthe middle magnetization direction Mb into the final magnetizationdirection Mc. The enhancement of the perpendicular component of thesecond torque RQ2 may be due to spin filtering at interfaces between thefirst conductive pattern 150 of a non-magnetic pattern and the secondconductive patterns 191 and 192 having the perpendicular magnetizationdirections. For example, the second pattern 192 may have theperpendicular magnetization direction Mu fixed in the second directionD2, and thus spin directions of the electrons transmitted into thesecond pattern 192 through the second lower contact plug 120B may bealigned in the second direction D2. The perpendicular component of thesecond torque RQ2 may be enhanced by the spin directions of theelectrons which are aligned in the second direction D2, and thus themiddle magnetization direction Mb may be more easily changed into thefinal magnetization direction Mc. In other words, deterministicswitching capable of accurately determining the final magnetizationdirection may be performed.

FIG. 5 illustrates a second in-plane current Jc2 that flows through thefirst conductive pattern 150 in the first direction D1. A currentprovided from the second selection element SW2 connected to aninterconnection line CL may sequentially pass through the second lowercontact plug 120B, the second pattern 192, the first conductive pattern150, the first pattern 191, and the first lower contact plug 120A andthen may be transmitted to the first selection element SW1. In thiscase, electrons may move from the first selection element SW1 to thesecond selection element SW2 through a path opposite to the above path.Like the descriptions of FIGS. 3 and 4, the first pattern 191 may havethe perpendicular magnetization direction Md fixed in the directionopposite to the second direction D2, and thus spin directions of theelectrons transmitted into the first pattern 191 through the first lowercontact plug 120A may be aligned in the direction opposite to the seconddirection D2. The perpendicular component of the second torque RQ2 maybe enhanced by the spin directions of the electrons which are aligned inthe direction opposite to the second direction D2, and thus an initialmagnetization direction Ma of the second direction D2 may be more easilychanged into a final magnetization direction Mc having the directionopposite to the second direction D2.

FIG. 6 is a plan view illustrating a magnetic memory device according tosome embodiments of the inventive concepts. Hereinafter, thedescriptions to the same components and features as in the aboveembodiments will be omitted for ease of explanation.

Referring to FIG. 6, magnetization directions of the first and secondmagnetic patterns MP1 and MP2 of the magnetic tunnel junction patternMTJ may be perpendicular to the top surface 100U of the substrate 100,as described with reference to FIGS. 3 and 5. The second in-planecurrent Jc2 in the first direction D1 or the first in-plane current Jc1in the direction opposite to the first direction D1 may flow in thefirst conductive pattern 150 through the first lower contact plug 120Aand the second lower contact plug 120B.

In the present embodiment, each of the second conductive patterns 191and 192 may have a magnetization direction fixed in a horizontaldirection, i.e., the in-plane direction. The magnetization direction ofeach of the second conductive patterns 191 and 192 may be fixed in adirection perpendicular to a direction in which the first pattern 191 isspaced apart from the second pattern 192. In other words, themagnetization direction of each of the second conductive patterns 191and 192 may be fixed in a direction perpendicular to the flowingdirections of the in-plane currents Jc1 and Jc2. For example, the secondpattern 192 may have a magnetization direction Mu fixed in the thirddirection D3, and the first pattern 191 may have a magnetizationdirection Md fixed in a direction opposite to the third direction D3.

Spin directions of electrons transmitted into the second pattern 192through the second lower contact plug 120B may be aligned in the thirddirection D3 by the magnetization direction Mu of the second pattern 192which is fixed in the third direction D3. A component, in the thirddirection D3 (i.e., a direction perpendicular to the in-plane current),of the second torque RQ2 described with reference to FIG. 4 may beenhanced by the spin directions of the electrons which are aligned inthe third direction D3, and this may induce the middle magnetizationdirection Mb to be more easily changed into the final magnetizationdirection Mc.

Likewise, spin directions of electrons transmitted into the firstpattern 191 through the first lower contact plug 120A may be aligned inthe opposite direction of the third direction D3 by the magnetizationdirection Md of the first pattern 191 which is fixed in the oppositedirection of the third direction D3. A component, in the oppositedirection of the third direction D3 (i.e., a direction perpendicular tothe in-plane current), of the second torque RQ2 described with referenceto FIG. 4 may be enhanced by the spin directions of the electrons whichare aligned in the opposite direction of the third direction D3, andthis may induce the middle magnetization direction Mb to be more easilychanged into the final magnetization direction Mc.

Referring again to FIGS. 1 and 2, the first conductive patterns 150 mayinclude a heavy metal or a material doped with a heavy metal. Forexample, the first conductive patterns 150 may include ‘A’ and/or ‘M’doped with ‘B’. The ‘A’ may include yttrium (Y), zirconium (Zr), niobium(Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh),palladium (Pd), cadmium (Cd), indium (In), antimony (Sb), tellurium(Te), hafnium (Hf), tantalum (Ta, including high-resistance amorphousβ-Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum(Pt), gold (Au), mercury (Hg), thallium (Tl), lead (Pb), bismuth (Bi),polonium (Po), astatine (At), and/or any combination thereof. The ‘B’may include vanadium (V), chromium (Cr), manganese (Mn), iron (Fe),cobalt (Co), nickel (Ni), phosphorus (P), sulfur (S), zinc (Zn), gallium(Ga), germanium (Ge), arsenic (As), selenium (Se), yttrium (Y),zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc),ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd),indium (In), antimony (Sb), tellurium (Te), iodine (I), lutetium (Lu),hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os),iridium (Ir), platinum (Pt), gold (Au), mercury (Hg), thallium (Tl),lead (Pb), bismuth (Bi), polonium (Po), astatine (At), lanthanum (La),cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm),samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium(Dy), holmium (Ho), erbium (Er), thulium (Tm), and/or ytterbium (Yb).The ‘M’ may include aluminum (Al), titanium (Ti), vanadium (V), chromium(Cr), manganese (Mn), copper (Cu), zinc (Zn), silver (Ag), hafnium (Hf),tantalum (Ta), tungsten (W), rhenium (Re), platinum (Pt), gold (Au),mercury (Hg), lead (Pb), silicon (Si), gallium (Ga), gallium-manganese(GaMn), and/or gallium-arsenide (GaAs). For example, the firstconductive patterns 150 may include copper (Cu) doped with iridium (Ir),and/or copper (Cu) doped with bismuth (Bi).

According to some embodiments, the second conductive patterns 191 and192 may be ferromagnetic patterns and may include a ferromagneticmaterial. In some embodiments, the magnetization directions Mu and Md ofthe second conductive patterns 191 and 192 may be substantiallyperpendicular to the interface between the tunnel barrier pattern TBPand the first magnetic pattern MP1. In this case, the second conductivepatterns 191 and 192 may include a perpendicular magnetic material(e.g., CoFeTb, CoFeGd, or CoFeDy), a perpendicular magnetic materialhaving a L1 ₀ structure, a CoPt alloy having a hexagonal close packed(HCP) lattice structure, and/or a perpendicular magnetic structure. Theperpendicular magnetic material having the L1 ₀ structure may includeFePt having the L1 ₀ structure, FePd having the L1 ₀ structure, CoPdhaving the L1 ₀ structure, and/or CoPt having the L1 structure. Theperpendicular magnetic structure may include magnetic layers andnon-magnetic layers, which are alternately and repeatedly stacked. Forexample, the perpendicular magnetic structure may include (Co/Pt)n,(CoFe/Pt)n, (CoFe/Pd)n, (Co/Pd)n, (Co/Ni)n, (CoNi/Pt)n, (CoCr/Pt)n,and/or (CoCr/Pd)n, where “n” denotes the number of bilayers. Here, thesecond conductive patterns 191 and 192 may be thicker than the freelayer (i.e., the first magnetic pattern MP1), and/or a coercive force ofthe second conductive patterns 191 and 192 may be greater than acoercive force of the first magnetic pattern MP1.

In certain embodiments, as illustrated in FIG. 6, the magnetizationdirections Mu and Md of the second conductive patterns 191 and 192 maybe substantially parallel to the interface between the tunnel barrierpattern TBP and the first magnetic pattern MP1. In this case, the secondconductive patterns 191 and 192 may further include ananti-ferromagnetic material for fixing a magnetization direction of aferromagnetic material.

A coercive force of the first patterns 191 may be greater than acoercive force of the second patterns 192. For example, the firstpatterns 191 may include at least one of the aforementioned materials, acoercive force of which is greater than the coercive force of the secondpatterns 192. In this case, the first patterns 191 may include adifferent material from that of the second patterns 192.

According to the embodiments of the inventive concepts, the firstconductive pattern 150 may more easily switch the magnetizationdirection of the first magnetic pattern MP corresponding to the freelayer by the second conductive patterns 191 and 192. The secondconductive patterns 191 and 192 may assist a final magnetizationdirection of the free layer to be perpendicularly aligned, and thus aspin current for switching of the magnetic memory device may be reduced.

FIGS. 7, 9, 11, 13, 15 and 17 are plan views illustrating a method ofmanufacturing a magnetic memory device, according to some embodiments ofthe inventive concepts. FIGS. 8, 10, 12, 14, 16 and 18 arecross-sectional views taken along lines I-I′ of FIGS. 7, 9, 11, 13, 15and 17, respectively. Hereinafter, the descriptions to the sametechnical features as in the embodiments of FIGS. 1 to 6 will be omittedor mentioned briefly for ease of explanation. Selection elements areomitted for ease of illustration.

Referring to FIGS. 7 and 8, a first interlayer insulating layer 111 maybe formed on a substrate 100. The substrate 100 may include asemiconductor substrate and selection elements (see SW of FIG. 2) formedon the semiconductor substrate. Lower contact plugs 120 may be formed inthe first interlayer insulating layer 111. In some embodiments, theformation of the lower contact plugs 120 may include forming lowercontact holes penetrating the first interlayer insulating layer 111, andforming the lower contact plugs 120 in the lower contact holes,respectively. Each of the lower contact plugs 120 may be connected toone terminal of a corresponding one of the selection elements.

A second interlayer insulating layer 112 may be formed to cover thelower contact plugs 120. The second interlayer insulating layer 112 maybe in contact with top surfaces of the lower contact plugs 120.

Referring to FIGS. 9 and 10, first openings OP1 may be formed topenetrate and extend through the second interlayer insulating layer 112.The first openings OP1 may expose the first lower contact plugs 120A.The first openings OP1 may have planar shapes similar to planar shapesof the first lower contact plugs 120A. However, embodiments of theinventive concepts are not limited thereto. The top surfaces of thesecond lower contact plugs 120B may not be exposed but may be covered bythe second interlayer insulating layer 112. In certain embodiments, thefirst openings OP1 may be formed by recessing upper portions of thelower contact plugs 120 (e.g., selectively recessing upper portions oflower contact plugs 120A) without the formation of the second interlayerinsulating layer 112.

Referring to FIGS. 11 and 12, first patterns 191 may be formed to fillthe first openings OP1, respectively. A process of forming the firstpatterns 191 may include depositing a ferromagnetic material to fill thefirst openings OP1, and performing a planarization process on thedeposited ferromagnetic material until a top surface of the secondinterlayer insulating layer 112 is exposed. The process of forming thefirst patterns 191 may include aligning magnetization directions of thefirst patterns 191 by a first external magnetic field. For example, thefirst patterns 191 may have the magnetization directions Md fixed in thedirection opposite to the second direction D2 by the aligning process,as illustrated in FIG. 3.

A mask layer 113 covering the first patterns 191 may be formed on thesecond interlayer insulating layer 112. Second openings OP2 exposing thesecond lower contact plugs 120B may be formed in the mask layer 113. Thesecond openings OP2 may penetrate and extend through the secondinterlayer insulating layer 112.

Referring to FIGS. 13 and 14, second patterns 192 may be formed to fillthe second openings OP2, respectively. A process of forming the secondpatterns 192 may include depositing a ferromagnetic material to fill thesecond openings OP2, and performing a planarization process on thedeposited ferromagnetic material until the top surface of the secondinterlayer insulating layer 112 is exposed. Thus, the first patterns 191and the second patterns 192 may be alternately arranged and spaced apartfrom one another in the first direction D1. Top surfaces of the firstpatterns 191 may be formed at substantially the same level as topsurfaces of the second patterns 192, and bottom surfaces of the firstpatterns 191 may be formed at substantially the same level as bottomsurfaces of the second patterns 192. However, embodiments of theinventive concepts are not limited thereto.

The process of forming the second patterns 192 may include aligningmagnetization directions of the second patterns 192 by a second externalmagnetic field. For example, the second patterns 192 may have themagnetization directions Mu fixed in the second direction D2 by thealigning process, as illustrated in FIG. 3. Since the coercive force ofthe first patterns 191 is greater than the coercive force of the secondpatterns 192, the magnetization directions Md of the first patterns 191described with reference to FIGS. 11 and 12 may not be changed by thesecond external magnetic field but may be maintained.

Referring to FIGS. 15 and 16, a first conductive layer 152 and amagnetic tunnel junction layer MTJL may be sequentially formed on thesecond conductive patterns 191 and 192. The first conductive layer 152may be formed by a sputtering process, a chemical vapor deposition (CVD)process, or an atomic layer deposition (ALD) process. The magnetictunnel junction layer MTJL may include a first magnetic layer ML1, atunnel barrier layer TBL, and a second magnetic layer ML2, which aresequentially stacked on the first conductive layer 152. Each of thefirst and second magnetic layers ML1 and ML2 may include at least onemagnetic layer. The tunnel barrier layer TBL may include a magnesiumoxide (MgO) layer, a titanium oxide (TiO) layer, an aluminum oxide (AlO)layer, a magnesium-zinc oxide (MgZnO) layer, and/or a magnesium-boronoxide (MgBO) layer. Each of the first magnetic layer ML1, the tunnelbarrier layer TBL and the second magnetic layer ML2 may be formed by asputtering process or a CVD process.

Electrode patterns 160 may be formed on the magnetic tunnel junctionlayer MTJL. The electrode patterns 160 may define regions in whichmagnetic tunnel junction patterns will be formed. For example, theelectrode patterns 160 may include a metal (e.g., Ta, W, Ru, or Ir)and/or a conductive metal nitride (e.g., TiN).

Referring to FIGS. 17 and 18, the magnetic tunnel junction layer MTJLand the first conductive layer 152 may be sequentially etched to formmagnetic tunnel junction patterns MTJ and first conductive patterns 150.Each of the first conductive patterns 150 may be disposed between a pairof the second conductive patterns 191 and 192 immediately adjacent toeach other in a plan view and may be connected to the pair of secondconductive patterns 191 and 192. Each of the second conductive patterns191 and 192 may be disposed between a pair of the first conductivepatterns 150 immediately adjacent to each other in a plan view, and maybe connected to the pair of first conductive patterns 150. A top surfaceof each of the second conductive patterns 191 and 192 may be in contactwith bottom surfaces of the first conductive patterns 150.

Each of the magnetic tunnel junction patterns MTJ may include a firstmagnetic pattern MP1, a tunnel barrier pattern TBP and a second magneticpattern MP2, which are sequentially stacked on each of the firstconductive patterns 150. The first magnetic pattern MP1 and the secondmagnetic pattern MP2 may be spaced apart from each other with the tunnelbarrier pattern TBP interposed therebetween.

The magnetic tunnel junction layer MTJL and the first conductive layer152 may be etched by, for example, an ion beam etching process. The ionbeam etching process may be performed by irradiating an ion beam ontothe substrate 100. The ion beam may be irradiated obliquely with respectto the top surface of the substrate 100. The ion beam may include inertions (e.g., argon positive ions (Ar⁺)). The ion beam etching process maybe performed using the electrode patterns 160 as masks.

Referring again to FIGS. 1 and 2, a third interlayer insulating layer170 may be formed to cover the magnetic tunnel junction patterns MTJ andthe electrode patterns 160. The third interlayer insulating layer 170may cover sidewalls of the magnetic tunnel junction patterns MTJ and theelectrode patterns 160. Upper conductive lines 200 (e.g., bit lines) maybe formed on the third interlayer insulating layer 170. Each of theupper conductive lines 200 may be connected to a corresponding one ofthe magnetic tunnel junction patterns MTJ through a corresponding one ofthe electrode patterns 160.

FIG. 19 is a cross-sectional view corresponding to the line I-I′ of FIG.1 to illustrate a magnetic memory device according to some embodimentsof the inventive concepts. Hereinafter, the descriptions to the samecomponents and features as in the above embodiments will be omitted forease of explanation.

Referring to FIG. 19, in a magnetic memory device according to thepresent embodiment, volumes (including lengths, widths,heights/thicknesses, and/or cross-sectional areas) of first patterns 191may be different from volumes of second patterns 192. For example, thevolume of each of the first patterns 191 may be greater than the volumeof each of the second patterns 192. For example, a cross-sectional areaof each of the first patterns 191 may be greater than a cross-sectionalarea of each of the second patterns 192. In the present embodiment, afirst thickness T1 of each of the first patterns 191 may be greater thana second thickness T2 of each of the second patterns 192. For example,the first thickness T1 may range from about 2 times to about 7 times thesecond thickness T2.

In the present embodiment, the first patterns 191 and the secondpatterns 192 may be formed of the same material. Since the volumes ofthe first patterns 191 are greater than the volumes of the secondpatterns 192, an effective coercive force of the first patterns 191 maybe greater than an effective coercive force of the second patterns 192.In the present specification, the effective coercive force may be acoercive force considering a volume of a corresponding pattern. Forexample, the effective coercive force may be determined by a thicknessof a corresponding pattern and/or an internal crystal structure (e.g., agrain size) of the corresponding pattern. Magnetization directions ofthe first and second patterns 191 and 192 may be the same as describedwith reference to FIGS. 3 to 6.

FIGS. 20 to 22 are cross-sectional views taken along the line I-I′ ofFIG. 1 to illustrate a method of manufacturing a magnetic memory device,according to some embodiments of the inventive concepts.

Referring to FIG. 20, upper portions of the first lower contact plugs120A in the structure of FIGS. 9 and 10 may be etched. For example, thefirst lower contact plugs 120A may be etched by a wet etching process.By the etching process, the first openings OP1 may extend between thesecond lower contact plugs 120B.

Referring to FIG. 21, a patterning process may be performed on thesecond interlayer insulating layer 112 to form second openings OP2exposing the second lower contact plugs 120B. In some embodiments, asacrificial layer may be formed to fill the first openings OP1, and thesacrificial layer may be removed after the formation of the secondopenings OP2. Depths of the second openings OP2 may be less than depthsof the first openings OP1.

Referring to FIG. 22, first patterns 191 filling the first openings OP1and second patterns 192 filling the second openings OP2 may be formed.The first patterns 191 and the second patterns 192 may be formed of thesame material at the same time by the same deposition process. Forexample, a ferromagnetic layer may be formed to fill the first openingsOP1 and the second openings OP2, and then, a planarization process maybe performed on the ferromagnetic layer until the second interlayerinsulating layer 112 is exposed.

A first external magnetic field may be applied to align magnetizationdirections of the first patterns 191 and magnetization directions of thesecond patterns 192 in the direction opposite to the second directionD2. Thereafter, a second external magnetic field weaker than the firstexternal magnetic field may be applied to align the magnetizationdirections of the second patterns 192 in the second direction D2. Theeffective coercive force of the first patterns 191 may be greater thanthat of the second patterns 192, and thus the magnetization directionsof the first patterns 191 may not be changed by the second externalmagnetic field but may be maintained in the direction opposite to thesecond direction D2. As a result, the magnetization directions of thefirst and second patterns 191 and 192 may have the directionsillustrated in FIG. 3.

Referring again to FIG. 19, the processes described with reference toFIGS. 15 to 19, 1 and 2 may be performed on the resultant structure ofFIG. 22. As a result, magnetic tunnel junction patterns MTJ, firstconductive patterns 150, electrode patterns 160 and upper conductivelines 200 may be formed.

FIG. 23 is a plan view illustrating a magnetic memory device accordingto some embodiments of the inventive concepts. FIG. 24 is across-sectional view taken along a line I-I′ of FIG. 23.

Referring to FIGS. 23 and 24, in a magnetic memory device according tothe present embodiment, volumes of first patterns 191 may be differentfrom volumes of second patterns 192. For example, a cross-sectional areaof each of the first patterns 191 may be less than a cross-sectionalarea of each of the second patterns 192. For example, a second width W2of the second pattern 192 in the first direction D1 may be greater thana first width W1 of the first pattern 191 in the first direction D1. Forexample, the second width W2 may range from about 1.5 times to about 3times the first width W1.

In the present embodiment, the first patterns 191 and the secondpatterns 192 may be formed of the same material. Since volumes of thefirst patterns 191 are less than volumes of the second patterns 192, aneffective coercive force of the first patterns 191 may be less than aneffective coercive force of the second patterns 192. Magnetizationdirections of the first and second patterns 191 and 192 may be the sameas described with reference to FIGS. 3 to 6.

FIGS. 25 and 27 are plan views illustrating a method of manufacturing amagnetic memory device, according to some embodiments of the inventiveconcepts. FIGS. 26 and 28 are cross-sectional views taken along linesI-I′ of FIGS. 25 and 27, respectively.

Referring to FIGS. 25 and 26, lower contact plugs 120 may be formed inthe first interlayer insulating layer 111. Widths of first lower contactplugs 120A in the first direction D1 may be different from widths ofsecond lower contact plugs 120B in the first direction D1. For example,the widths of the second lower contact plugs 120B may be greater thanthe widths of the first lower contact plugs 120A. Alternatively, thewidths of the second lower contact plugs 120B may be substantially equalto the widths of the first lower contact plugs 120A. Thereafter, asecond interlayer insulating layer 112 may be deposited.

Referring to FIGS. 27 and 28, first openings OP1 exposing the firstlower contact plugs 120A and second openings OP2 exposing the secondlower contact plugs 120B may be formed in the second interlayerinsulating layer 112. A second width W2 of the second opening OP2 in thefirst direction D1 may be greater than a first width W1 of the firstopening OP1 in the first direction D1.

Thereafter, first patterns 191 may be formed in the first openings OP1,respectively, and second patterns 192 may be formed in the secondopenings OP2, respectively. The first patterns 191 and the secondpatterns 192 may be formed of the same material at the same time by thesame deposition process. For example, a ferromagnetic layer may beformed to fill the first openings OP1 and the second openings OP2, andthen, a planarization process may be performed on the ferromagneticlayer until the second interlayer insulating layer 112 is exposed.

A first external magnetic field may be applied to align magnetizationdirections of the first patterns 191 and magnetization directions of thesecond patterns 192 in the second direction D2. Thereafter, a secondexternal magnetic field weaker than the first external magnetic fieldmay be applied to align the magnetization directions of the firstpatterns 191 in the direction opposite to the second direction D2. Theeffective coercive force of the second patterns 192 may be greater thanthat of the first patterns 191, and thus the magnetization directions ofthe second patterns 192 may not be changed by the second externalmagnetic field but may be maintained in the second direction D2. As aresult, the magnetization directions of the first and second patterns191 and 192 may have the directions illustrated in FIG. 3.

Referring again to FIG. 24, the processes described with reference toFIGS. 15 to 19, 1 and 2 may be performed on the resultant structure ofFIG. 28. As a result, magnetic tunnel junction patterns MTJ, firstconductive patterns 150, electrode patterns 160 and upper conductivelines 200 may be formed.

FIG. 29 is a cross-sectional view taken along the line I-I′ of FIG. 1 toillustrate a magnetic memory device according to some embodiments of theinventive concepts. In the present embodiment, separate lower contactplugs 120A and 120B under second conductive patterns 191 and 192 may beomitted, and the second conductive patterns 191 and 192 may be used asthe lower contact plugs 120A and 120B, respectively.

FIG. 30 is a cross-sectional view taken along the line I-I′ of FIG. 1 toillustrate a magnetic memory device according to some embodiments of theinventive concepts. In the present embodiment, a first conductivepattern 150 may not be cut or divided between the magnetic tunneljunction patterns MTJ but may have a linear or line shape continuouslyextending in the first direction D1. Thus, the first conductive pattern150 may continuously extend in the first direction D1 and may bealternately connected to the first patterns 191 and the second patterns192, which are spaced apart along the first direction D1.

According to the embodiments of the inventive concepts, the magneticmemory device capable of reducing a switching current may be provided.According to the embodiments of the inventive concepts, it is possibleto provide the magnetic memory device capable of allowing themagnetization direction of the free layer to be more easily aligned inthe perpendicular direction after switching the free layer.

While the inventive concepts have been described with reference toexample embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirits and scopes of the inventive concepts. Therefore, itshould be understood that the above embodiments are not limiting, butillustrative. Thus, the scopes of the inventive concepts are to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing description.

1. A magnetic memory device comprising: a magnetic tunnel junctionpattern on a substrate; a first conductive pattern between the substrateand the magnetic tunnel junction pattern; lower contact plugs betweenthe first conductive pattern and the substrate and disposed atrespective sides of the magnetic tunnel junction pattern; and secondconductive patterns on the lower contact plugs, respectively, whereinthe second conductive patterns connect the lower contact plugs to thefirst conductive pattern, wherein the second conductive patternscomprise a ferromagnetic material.
 2. The magnetic memory device ofclaim 1, wherein first and second patterns of the second conductivepatterns are connected to first and second end portions of the firstconductive pattern, respectively.
 3. The magnetic memory device of claim1, wherein the second conductive patterns comprise: a first patterndisposed at one side of the first conductive pattern; and a secondpattern disposed at another side of the first conductive pattern,wherein the first and second patterns have first and secondmagnetization directions, respectively, that are fixed in oppositedirections to each other.
 4. The magnetic memory device of claim 3,wherein the first pattern has the first magnetization direction fixed ina direction perpendicular to a top surface of the substrate, and whereinthe second pattern has the second magnetization direction fixed in adirection opposite to the first magnetization direction of the firstpattern.
 5. The magnetic memory device of claim 3, wherein the firstpattern and the second pattern are spaced apart from each other in afirst direction parallel to a top surface of the substrate, and whereinthe first and second magnetization directions are parallel to a seconddirection which is parallel to the top surface of the substrate andintersects the first direction.
 6. The magnetic memory device of claim3, wherein the first pattern and the second pattern comprise differentmaterials from each other.
 7. The magnetic memory device of claim 3,wherein the first pattern and the second pattern have substantiallyequal thicknesses and substantially equal widths.
 8. The magnetic memorydevice of claim 3, wherein the first pattern and the second pattern havedifferent volumes from each other.
 9. The magnetic memory device ofclaim 8, wherein the first pattern and the second pattern comprise asame material.
 10. The magnetic memory device of claim 3, wherein thefirst pattern and the second pattern have different thicknesses fromeach other.
 11. The magnetic memory device of claim 3, wherein the firstpattern and the second pattern have different widths from each other.12. (canceled)
 13. (canceled)
 14. A magnetic memory device comprising:magnetic tunnel junction patterns arranged along and spaced apart in afirst direction on a substrate; first conductive patterns under bottomsurfaces of the magnetic tunnel junction patterns, respectively; andlower conductive patterns between the substrate and the first conductivepatterns, wherein the lower conductive patterns are disposed between themagnetic tunnel junction patterns in a plan view and connect adjacentones of the first conductive patterns, wherein the lower conductivepatterns comprise first lower conductive patterns and second lowerconductive patterns, which are alternately arranged in the firstdirection, and wherein the first lower conductive patterns and thesecond lower conductive patterns have first and second magnetizationdirections, respectively, that are fixed in opposite directions to eachother.
 15. The magnetic memory device of claim 14, wherein the first andsecond magnetization directions are perpendicular to a top surface ofthe substrate.
 16. The magnetic memory device of claim 14, wherein thefirst and second magnetization directions are parallel to a seconddirection which is parallel to a top surface of the substrate andintersects the first direction.
 17. The magnetic memory device of claim14, wherein the first lower conductive patterns and the second lowerconductive patterns comprise different materials from each other. 18.The magnetic memory device of claim 14, wherein the first lowerconductive patterns and the second lower conductive patterns havedifferent thicknesses or different widths from each other. 19.-21.(canceled)
 22. A magnetic memory device comprising: magnetic tunneljunction patterns arranged along and spaced apart in a first directionon a substrate; first conductive patterns under bottom surfaces of themagnetic tunnel junction patterns, respectively; and second conductivepatterns between the substrate and the first conductive patterns andincluding a ferromagnetic material, wherein the second conductivepatterns are disposed between the magnetic tunnel junction patterns in aplan view and connect adjacent ones of the first conductive patterns,wherein the second conductive patterns comprise: first patterns disposedat first sides of the first conductive patterns; and second patternsdisposed at second sides of the first conductive patterns, wherein across-sectional area of each of the second patterns is greater than across-sectional area of each of the first patterns.
 23. The magneticmemory device of claim 22, wherein the first patterns and the secondpatterns comprise a same material.
 24. The magnetic memory device ofclaim 23, wherein first thicknesses or widths of the first patterns aredifferent from second thicknesses or widths of the second patterns. 25.The magnetic memory device of claim 23, wherein first widths of thefirst patterns are different from second widths of the second patterns.26. (canceled)